1. Field of the Invention
The present invention relates to an image forming apparatus such as a copier, printer, facsimile and the like, which forms an image on a sheet.
2. Description of Related Art
Lately, an image forming apparatus is known which includes a function to divide a plurality of page image data into a plurality of groups (hereinafter referred to as chapter) or when an image is formed on sheets according to the page image data, a function to insert a sheet (hereinafter referred to as interleaving sheet) between a stack of sheets with a different color with respect to chapters so that the stack of sheets can be discerned with respect to chapters.
For example, Japanese Patent Application Laid-Open Publication No. 7-13470 discloses an image forming apparatus which is provided with a chapter division section which forms an image of an image data of a designated page of a document on a front of a sheet then prints the pages of the document after the designated page on the back and the front of the sheet in this order, and a sheet interleaving section to print a designated document on a surface of a specific interleaving sheet.
Japanese Patent Application Laid-Open Publication No. 2004-112236 discloses an image forming apparatus which includes a function to print a stamp on interleaving sheets for dividing chapters which enables setting the printing color of the stamp the same color as the selected color mode (for example, a color different from the printing color for sheets other than the interleaving sheet) and which enables a user to set the printing position of the stamp to a desired position.
However, with the above image forming apparatuses, the interleaving sheets are used so as to identify from appearance the sheets with the image formed with respect to chapter, thus depending on the type of interleaving sheet, it is difficult to discern the division of the chapters. When a stamp is printed on an interleaving sheet, it is complicated for a user to freely set a printing position of the stamp, and when a plurality of sheets including a plurality of chapters are stacked, it is difficult to discern at one glance the division of the chapters by printed stamps.